Bar codes have been used in a wide variety of applications as a source for information. Typically bar codes are used at a point-of-sale terminal in merchandising for pricing and inventory control. Bar codes are also used in controlling personnel access systems, mailing systems, and in manufacturing for work-in process and inventory control systems, etc. The bar codes themselves represent alphanumeric characters by series of adjacent stripes of various widths, i.e. the universal product code.
A bar code is a set of binary numbers. It consists of black bars and white spaces. A wide black bar space signifies a one and a thin black bar or space signifies a zero. The binary numbers stand for decimal numbers or letters. There are several different kinds of bar codes. In each one, a number, letter or other character is formed by a certain number or bars and spaces.
Bar code reading systems or scanners have been developed to read bar codes. The bar code may be read by having a light beam translated across the bar code and a portion of the light illuminating the bar code is reflected and collected by a scanner. The intensity of the reflected light is proportional to the reflectance of the area illuminated by the light beam. Thus, the scanners read the difference between the light and dark bars by reading the absences of reflected light. This light is converted into an electric current signal and then the signal is decoded.
Bar codes have been affixed to many different types of documents, so that they may be read by a machine, thereby reducing labor costs. Documents that include bar codes and/or indicia have been issued by governmental agencies, financial institutions, brokerage houses, etc., that authorize the holder of such documents to perform authorized tasks or grant rights to the holder of such a document. Examples of such documents are drivers licenses, entry access badges, identification cards, etc.
Information has been recorded on magnetic tape by magnetizing narrow lengthwise strips or tracks on the magnetic tape in a pattern corresponding to a sequence of binary states. Binary data is stored in one or more tracks across the width of the tape. A read head is usually associated with each track of magnetized material in order to read the information stored in the tracks.
Magnetic strips have been affixed to many different types of documents, so that they may be read by a machine, thereby reducing labor costs. Documents that include magnetic strips have been issued by governmental agencies, financial institutions, etc., that authorize the holder of such documents to perform authorized tasks or grant rights to the holder of such a document. Examples of such documents are drivers licenses, credit cards, automatic teller machine cards, etc.
In issuing government documents and other documents, it is desirable to have them of a convenient size, while including information necessary for identifying the holder with the rights conferred. With the above two requirements, documents issued by government agencies and others not only will have a defined format, but the textual information printed thereon is dense, thereby leaving little or no room for any additional information to be printed thereon.
Thus, a problem of the prior art is to issue documents of a convenient size that contains a large amount of information that may be read by a human and/or a machine.
Another problem of the prior art is to issue documents of a convenient size that contain a large amount of information and are difficult to alter or forge.